This invention relates to processes for extracting oxygen and metallic iron from iron oxide-containing ores such as ilmenite and, more particularly, to such processes which can be used at lunar or other space station installations.
Many prior techniques for extracting oxygen and metallic iron from lunar rocks, such as hydrogen reduction or carbothermal reduction of ilmenite or electrowinning of molten silicates, require temperatures in excess of 900.degree. C. Such techniques are not practical for many applications because they require refractory materials and heavy insulation which results in high construction costs for full scale installations and operational costs are quite high, particularly energy costs. Also, the only useful material directly produced by the hydrogen reduction of ilmenite is gaseous oxygen.
U.S. Pat. No. to Turner et al, U.S. Pat. No. 2,441,856 discloses a cyclical process for producing titanium dioxide from ilmenite. However, that process is designed primarily for recovering titanium dioxide pigments and does not produce oxygen.
U.S. Pat. No. 1,420,128to Moxham, U.S. Pat. No. 1,420,129 to Moxham and U.S. Pat. No. to Fahlstrom et al, U.S. Pat. No. 4,060,464 disclose processes for extracting iron from iron-bearing ores and recovering iron by electrolysis. U.S. Pat. No. 3,529,931 to Moklebust discloses a process for regenerating hydrochloric acid from an iron chloride solution derived from leaching a titaniferous ore, such as ilmenite. U.S. Pat. No. to Traini et al, U.S. Pat. No. 4,230,542 discloses an electrolytic process for treating a hydrochloric acid ilmenite leach solution to reduce ferric ions to ferrous ions.